Over the last 20 years, Computer-Supported Cooperative Work (CSCW) has identified a base set of findings. These findings are taken almost as assumptions within the field. In summary, they argue that human activity is highly flexible, nuanced, and contextualized and that computational entities such as information transfer, roles, and policies need to be similarly flexible, nuanced, and contextualized. However, current systems cannot fully support the social world uncovered by these findings. This talk argues there is an inherent gap between social requirements and technical mechanisms: The social-technical gap is the divide between what we know we must support socially and what we can support technically. Exploring, understanding, and hopefully ameliorating this social-technical gap is the central challenge for CSCW and social computing as intellectual endeavors, and it is also one of the central problems for Human-Computer Interaction in general. The talk also considers CSCW (and social computing) as a potential Simonian science of the artificial, so as to uncover potential ways around the gap.